diff --git a/provider/diag/diagnostics.go b/provider/diag/diagnostics.go
index c302521d..76de1dbb 100644
--- a/provider/diag/diagnostics.go
+++ b/provider/diag/diagnostics.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"reflect"
+	"sort"
 	"strings"
 
 	"github.com/hashicorp/errwrap"
@@ -12,6 +13,8 @@ import (
 
 type Diagnostics []Diagnostic
 
+var _ sort.Interface = (*Diagnostics)(nil)
+
 func (diags Diagnostics) Error() string {
 	switch {
 	case len(diags) == 0:
diff --git a/provider/diag/diagnostics_test.go b/provider/diag/diagnostics_test.go
index bfb05a6c..79ca2f11 100644
--- a/provider/diag/diagnostics_test.go
+++ b/provider/diag/diagnostics_test.go
@@ -13,7 +13,7 @@ func TestDiagnostics_Squash(t *testing.T) {
 	testCases := []struct {
 		Name  string
 		Value Diagnostics
-		Want  []FlatDiag
+		Want  FlatDiags
 	}{
 		{
 			Name: "simple squash no details",
@@ -21,7 +21,7 @@ func TestDiagnostics_Squash(t *testing.T) {
 				NewBaseError(errors.New("error test"), RESOLVING, WithResourceName("a"), WithSummary("some summary")),
 				NewBaseError(errors.New("error test"), RESOLVING, WithResourceName("a"), WithSummary("some summary")),
 			},
-			Want: []FlatDiag{
+			Want: FlatDiags{
 				{
 					Err:      "error test",
 					Resource: "a",
@@ -44,7 +44,7 @@ func TestDiagnostics_Squash(t *testing.T) {
 				NewBaseError(errors.New("error test2"), RESOLVING, WithResourceName("a"), WithSummary("some summary2"), WithDetails("some details2.")),
 				NewBaseError(errors.New("error test2"), RESOLVING, WithResourceName("a"), WithSummary("some summary2"), WithDetails("some details2.")),
 			},
-			Want: []FlatDiag{
+			Want: FlatDiags{
 				{
 					Err:      "error test",
 					Resource: "a",
@@ -77,7 +77,7 @@ func TestDiagnostics_Squash(t *testing.T) {
 				NewBaseError(errors.New("error test"), RESOLVING, WithResourceName("a"), WithSummary("some summary")),
 				NewBaseError(errors.New("error test"), RESOLVING, WithResourceName("b"), WithSummary("some summary")),
 			},
-			Want: []FlatDiag{
+			Want: FlatDiags{
 				{
 					Err:      "error test",
 					Resource: "a",
@@ -110,7 +110,7 @@ func TestDiagnostics_Squash(t *testing.T) {
 				NewBaseError(errors.New("error test"), RESOLVING, WithSeverity(WARNING), WithResourceName("a"), WithSummary("some summary")),
 				NewBaseError(errors.New("error test"), RESOLVING, WithResourceName("a"), WithSummary("some summary")),
 			},
-			Want: []FlatDiag{
+			Want: FlatDiags{
 				{
 					Err:      "error test",
 					Resource: "a",
@@ -160,7 +160,7 @@ func TestDiagnostics_SquashRedactable(t *testing.T) {
 	}
 	out := input.Squash()
 
-	assert.Equal(t, []FlatDiag{
+	assert.Equal(t, FlatDiags{
 		{
 			Err:      "error test: 123",
 			Resource: "a",
@@ -188,7 +188,7 @@ func TestDiagnostics_SquashRedactable(t *testing.T) {
 	r := rd.Redacted()
 	assert.NotNil(t, r)
 
-	assert.Equal(t, []FlatDiag{
+	assert.Equal(t, FlatDiags{
 		{
 			Err:      "error test: xxx",
 			Resource: "a",
diff --git a/provider/diag/flat.go b/provider/diag/flat.go
index e5b5888d..cbc49c4c 100644
--- a/provider/diag/flat.go
+++ b/provider/diag/flat.go
@@ -1,5 +1,7 @@
 package diag
 
+import "sort"
+
 // FlatDiag is a structured diagnostic, usually can be used to create a json of diagnostics or testing.
 type FlatDiag struct {
 	Err         string
@@ -11,9 +13,13 @@ type FlatDiag struct {
 	Description Description
 }
 
+type FlatDiags []FlatDiag
+
+var _ sort.Interface = (*FlatDiags)(nil)
+
 // FlattenDiags converts Diagnostics to an array of FlatDiag
-func FlattenDiags(dd Diagnostics, skipDescription bool) []FlatDiag {
-	df := make([]FlatDiag, len(dd))
+func FlattenDiags(dd Diagnostics, skipDescription bool) FlatDiags {
+	df := make(FlatDiags, len(dd))
 	for i, d := range dd {
 		description := d.Description()
 		df[i] = FlatDiag{
@@ -32,3 +38,20 @@ func FlattenDiags(dd Diagnostics, skipDescription bool) []FlatDiag {
 	}
 	return df
 }
+
+func (diags FlatDiags) Len() int      { return len(diags) }
+func (diags FlatDiags) Swap(i, j int) { diags[i], diags[j] = diags[j], diags[i] }
+func (diags FlatDiags) Less(i, j int) bool {
+	if diags[i].Severity > diags[j].Severity {
+		return true
+	} else if diags[i].Severity < diags[j].Severity {
+		return false
+	}
+
+	if diags[i].Type > diags[j].Type {
+		return true
+	} else if diags[i].Type < diags[j].Type {
+		return false
+	}
+	return diags[i].Description.Resource < diags[j].Description.Resource
+}